In a new documentary, “The Dog,” filmmakers Allison Berg and Frank Keraudren tell the story of John Wojtowicz, the inspiration for Al Pacino’s character in “Dog Day Afternoon.”

Wojtowicz robbed a bank to raise money for his lover’s sex change operation. Ernest Aron, who became Elizabeth Eden, was driven to transition from male to female -- Wojtowicz orchestrated the robbery of a Brooklyn branch of Chase Manhattan as a labor of love.

The incident resulted in the death of one of his accomplices and a 20-year sentence for Wojtowicz (he would only serve five). In the 10-year making of “The Dog,” Berg and Keraudren spoke with Wojtowicz’s family, his former allies in the gay rights movement, and one of his former hostages.

What impact did this self-described “Dog” have on the gay right’s movement? What’s the truth behind “Dog Day Afternoon”?